The overall objectives of this project are to define for the lung the interrelationship of physiological performance, biochemical composition, and chemical potential of specific cells and the morphological character and arrangement of pulmonary tissue components. The experimental design involves the study of the chemical composition of the lung in normal human subjects of various ages, in animal models of pulmonary injury and in diverse forms of obstructive lung disease. Functional relationships involve the interrelation of mechanical characteristics of whole lungs regionally and the distribution of stresses throughout the lung in normal and diseased states. Biochemically, the project focuses on the precise chemical composition of connective tissue components, i.e. elastin, collagen and glycoproteins, in normal pulmonary parenchyma, in experimentally induced pulmonary disease in animals and clinically encountered obstructive lung disease in man. Morphological characteristics of connective tissue and whole lung structure will be defined by light and electron microscopy. The assessment of structural functional relationships will extend to the qualitative and quantitative analysis of the role of whole lung tissue in the formation, inactivation and modification of vasoactive substances which affect systemic and local vasomotor control. Emphasis will be placed on the interdependence of lung function at the biochemical and morphological level and physiological performance of the lung in the normal and diseased state. BIBLIOGRAPHIC REFERENCES: Rodriguez, J. R., Seals, J. E., Radin, A., Lin, J. S., Mandl, I. and Turino, G.M. The role of leukocyte lysosomal elastase in the pathogenesis of obstructive lung disease. Abstract. Clin. Res. 23:351A, 1975. Fierer, J. A., Cerreta, J. M., Turino, G. M. and Mandl, I. Ultrastructural studies of lung elastin in elastase-induced emphysema. Abstract. Am. J. Path. Feb. 1976.